DESCRIPTION

Stinging caterpillars are the immature stages of several species
of moths. They may possess short spines or be densely covered
with long hairs. Some of the more common stinging species are
described below.

The Io moth larva is pea-green and has greenish spines tipped
with black. A reddish stripe edged with white extends down the
entire length of the larva's abdomen. The Io moth caterpillar is
about 60 mm long when fully grown.

One of the flannel moth caterpillars, sometimes known as the
hackberry leaf slug, has a few long, plumose setae in its early
instars. In later instars, the long setae are more noticeable
and there is a short, heavy spine adjacent to each spiracle.
This spotted caterpillar is about 24 mm long when fully grown.

The puss caterpillar is roughly pear-shaped and densely covered
with hair-like setae. The long setae may be pale yellow, gray,
reddish-brown or light brown. This larva is about 25 mm long
when fully grown.

The saddleback is one of the more distinctive stinging
caterpillars. Its short, stout green body has a white saddle-shaped spot with a
bright,
purplish-brown center. Its thoracic
legs are very tiny and no prolegs are present. This caterpillar
grows to about 25 mm long when fully grown.

BIOLOGY

Distribution -- The distribution of stinging caterpillars
varies with species. However, most species are found throughout
the U.S.

Hosts -- All stinging caterpillars are foliage-feeding
insects. Trees, ornamentals, field crops, and fruits all support
infestations of stinging caterpillars.

Damage -- Stinging caterpillars are covered with hair-like,
fragile hollow spines filled with an urticating venom. When the
spines are broken by contact, venom passes through the spines
onto the skin of people who come in contact with them. Burning,
pain, swelling, and/or prolonged itching may result. In some
cases, local lesions may persist for several days.

Life History -- Because there are several species of
stinging caterpillars, a specific life history cannot be given
which would apply for all. In general, moths fly during the
summer and lay eggs. Caterpillars hatch and grow as they feed
for several weeks. The caterpillars then pupate and ultimately
new moths emerge. These insects hibernate as eggs, prepupae, or
pupae, depending on the species. In any case, the caterpillars
usually occur only in summer.

CONTROL

These insects are usually uncommon and usually no control
procedures are warranted. However, if particularly large
populations develop, they can be treated with insecticides like
other leaf-feeding caterpillars.